IPTV is a multimedia delivery platform that utilizes a packet-based network infrastructure (e.g., broadband Internet access networks) to deliver video content to customers, typically as an alternative to delivery by traditional over-the-air television, satellite television, and cable television. A typical IPTV solution includes head-end video acquisition equipment for receiving television content, intermediate IPTV facilities (e.g., Ericsson Mediaroom™) including server platforms and associated IPTV middleware, networking devices (e.g., routers, switches) for content distribution between various nodes of the IPTV system, access nodes (e.g., very-high-bit-rate digital subscriber line (VDSL or VHDSL) or passive optical network (PON) equipment) to enable high-bandwidth transport to and from the customer premises, and operator-provided applications that manage the IPTV system and/or provide end-user IPTV applications.
Consumers (also referred to as users, end users, viewers, customers, or subscribers) of IPTV services utilize user interfaces of operator-provided applications on User Equipment (UE) devices (such as set-top boxes (STBs), tablets, smartphones, laptops, personal computers, etc.) to access IPTV content. However, these applications are difficult to create, as they are often tremendously complex systems including many layers of abstraction and rely upon customized code bases. Further, it is also desired, by operators, to provide custom application user interfaces (UIs) for different users or devices, and it has proven tremendously difficult to both generate and maintain such custom UIs.
The appearance and behavior of UIs for web applications are typically pre-defined. The code that defines it—CSS, for the most part—is fixed past compile-time and typically statically referenced by a web application.
Although some applications may permit “skinning” for the purposes of app customization, many applications (e.g., those of large companies) require a great deal of customization far beyond what “skinning” can provide, as there is a need to be able to control how user interface elements should look and/or behave—perhaps radically differently. To satisfy such requirements, some application developers have turned to digging into code bases and (statically) applying such customizations. This usually requires expert knowledge of the code base, and can lead to many unintended bugs being created. Accordingly, there is a need for a solution for modifying complex web applications that allows creating widely differing UI experiences, depending on developer preference, without requiring code base changes.
Cascading Style Sheet (CSS) pre-processors have been one approach recently used to more easily build rich web technology based applications that can be customized. However, CSS pre-processors are typically designed to be run as part of a build step to produce static CSS files that can then be used directly by browsers without additional customization. Additionally, some CSS pre-processors perform all parsing, transforming, and variable replacement in one computationally expensive step on the client side, thereby degrading the performance and user experience. Accordingly, there is still a need for generating and maintaining per-user (or per-device) style customization of web application, at a significantly smaller footprint such that it could be suitable for highly customized CSS that can be generated on-demand by web servers or by web browsers.